uTools-Manuals/docs/php/maxdb_field_seek.html
2019-04-28 19:00:34 +08:00

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<title>Set result pointer to a specified field offset</title>
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<div id="layout-content"><div id="function.maxdb-field-seek" class="refentry">
<div class="refnamediv">
<h1 class="refname">maxdb_field_seek</h1>
<h1 class="refname">maxdb_result::field_seek</h1>
<p class="verinfo">(PECL maxdb &gt;= 1.0)</p><p class="refpurpose"><span class="refname">maxdb_field_seek</span> -- <span class="refname">maxdb_result::field_seek</span> &mdash; <span class="dc-title">Set result pointer to a specified field offset</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.maxdb-field-seek-description">
<h3 class="title">说明</h3>
<p class="para">过程化风格</p>
<div class="methodsynopsis dc-description">
<span class="methodname"><strong>maxdb_field_seek</strong></span>
( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$result</code></span>
, <span class="methodparam"><span class="type">int</span> <code class="parameter">$fieldnr</code></span>
) : <span class="type">bool</span></div>
<p class="para rdfs-comment">面向对象风格</p>
<div class="methodsynopsis dc-description">
<span class="methodname"><strong>maxdb_result::field_seek</strong></span>
( <span class="methodparam"><span class="type">int</span> <code class="parameter">$fieldnr</code></span>
) : <span class="type">bool</span></div>
<p class="para rdfs-comment">
Sets the field cursor to the given offset. The next call to <span class="function"><a href="maxdb_fetch_field.html" class="function">maxdb_fetch_field()</a></span>
will retrieve the field definition of the column associated with that offset.
</p>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">To seek to the beginning of a row, pass an offset value of zero.</p>
</p></blockquote>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.maxdb-field-seek-returnvalues">
<h3 class="title">返回值</h3>
<p class="para">
<span class="function"><strong>maxdb_field_seek()</strong></span> returns previuos value of field cursor.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.maxdb-field-seek-examples">
<h3 class="title">范例</h3>
<div class="example" id="example-1361">
<p><strong>Example #1 面向对象风格</strong></p>
<div class="example-contents">
<div class="phpcode"><pre><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br />$maxdb&nbsp;</span><span style="color: #007700">=&nbsp;new&nbsp;</span><span style="color: #0000BB">maxdb</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"MONA"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"RED"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"DEMODB"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;check&nbsp;connection&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">maxdb_connect_errno</span><span style="color: #007700">())&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Connect&nbsp;failed:&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">maxdb_connect_error</span><span style="color: #007700">());<br />&nbsp;&nbsp;&nbsp;exit();<br />}<br /><br /></span><span style="color: #0000BB">$query&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">"SELECT&nbsp;name,&nbsp;cno&nbsp;from&nbsp;hotel.customer&nbsp;ORDER&nbsp;BY&nbsp;cno"</span><span style="color: #007700">;<br /><br />if&nbsp;(</span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">$maxdb</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">query</span><span style="color: #007700">(</span><span style="color: #0000BB">$query</span><span style="color: #007700">))&nbsp;{<br /><br />&nbsp;&nbsp;&nbsp;</span><span style="color: #FF8000">/*&nbsp;Get&nbsp;field&nbsp;information&nbsp;for&nbsp;2nd&nbsp;column&nbsp;*/<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$result</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">field_seek</span><span style="color: #007700">(</span><span style="color: #0000BB">1</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$finfo&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">$result</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">fetch_field</span><span style="color: #007700">();<br /><br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Name:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$finfo</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">name</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Table:&nbsp;&nbsp;&nbsp;&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$finfo</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">table</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"max.&nbsp;Len:&nbsp;%d\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$finfo</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">max_length</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Flags:&nbsp;&nbsp;&nbsp;&nbsp;%d\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$finfo</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">flags</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Type:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;%d\n\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$finfo</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">type</span><span style="color: #007700">);<br /><br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$result</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">close</span><span style="color: #007700">();<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;close&nbsp;connection&nbsp;*/<br /></span><span style="color: #0000BB">$maxdb</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">close</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</pre></div>
</div>
</div>
<div class="example" id="example-1362">
<p><strong>Example #2 过程化风格</strong></p>
<div class="example-contents">
<div class="phpcode"><pre><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br />$link&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">maxdb_connect</span><span style="color: #007700">(</span><span style="color: #DD0000">"localhost"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"MONA"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"RED"</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"DEMODB"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/*&nbsp;check&nbsp;connection&nbsp;*/<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">maxdb_connect_errno</span><span style="color: #007700">())&nbsp;{<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Connect&nbsp;failed:&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">maxdb_connect_error</span><span style="color: #007700">());<br />&nbsp;&nbsp;&nbsp;exit();<br />}<br /><br /></span><span style="color: #0000BB">$query&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">"SELECT&nbsp;name,&nbsp;cno&nbsp;from&nbsp;hotel.customer&nbsp;ORDER&nbsp;BY&nbsp;cno"</span><span style="color: #007700">;<br /><br />if&nbsp;(</span><span style="color: #0000BB">$result&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">maxdb_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$query</span><span style="color: #007700">))&nbsp;{<br /><br />&nbsp;&nbsp;&nbsp;</span><span style="color: #FF8000">/*&nbsp;Get&nbsp;field&nbsp;information&nbsp;for&nbsp;2nd&nbsp;column&nbsp;*/<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">maxdb_field_seek</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">1</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">$finfo&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">maxdb_fetch_field</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br /><br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Name:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$finfo</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">name</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Table:&nbsp;&nbsp;&nbsp;&nbsp;%s\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$finfo</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">table</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"max.&nbsp;Len:&nbsp;%d\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$finfo</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">max_length</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Flags:&nbsp;&nbsp;&nbsp;&nbsp;%d\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$finfo</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">flags</span><span style="color: #007700">);<br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">printf</span><span style="color: #007700">(</span><span style="color: #DD0000">"Type:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;%d\n\n"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$finfo</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">type</span><span style="color: #007700">);<br /><br />&nbsp;&nbsp;&nbsp;</span><span style="color: #0000BB">maxdb_free_result</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">);<br />}<br /><br /></span><span style="color: #FF8000">/*&nbsp;close&nbsp;connection&nbsp;*/<br /></span><span style="color: #0000BB">maxdb_close</span><span style="color: #007700">(</span><span style="color: #0000BB">$link</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</pre></div>
</div>
</div>
<p class="para">以上例程的输出类似于:</p>
<div class="example-contents screen">
<div class="cdata"><pre>
Name: NAME
Table:
max. Len: 10
Flags: -1
Type: 2
</pre></div>
</div>
</div>
<div class="refsect1 seealso" id="refsect1-function.maxdb-field-seek-seealso">
<h3 class="title">参见</h3>
<p class="para">
<ul class="simplelist">
<li class="member"><span class="function"><a href="maxdb_fetch_field.html" class="function" rel="rdfs-seeAlso">maxdb_fetch_field()</a> - Returns the next field in the result set</span></li>
</ul>
</p>
</div>
</div></div></div></body></html>